1. Field of the Invention
The present invention is broadly concerned with a high efficiency fill assembly designed for use in crossflow water cooling towers and which makes optimum use of the desirable qualities of both film and splash-type fill components. More particularly, it is concerned with such a combination fill assembly wherein the more expensive and effective film fill portions are strategically located within the overall assembly for maximum cooling effect, whereas the splash components are situated throughout the remainder of the overall assembly.
2. Description of the Prior Art
Crossflow water cooling towers are today in widespread use and generally include an upper hot water distribution basin for receiving and distributing quantities of initially hot water, along with a fill structure beneath the basin for even distribution of the descending, initially hot water. Means such as powered fans or a hyperbolic stack are also provided, in order to draw ambient-derived cooling air currents through the fill structure in crossflowing, intersecting, heat exchanging relationship with the descending water. Cooled water is then collected in an underlying basin, whereas hot, moist air is discharged to the atmosphere.
Considerable research has been conducted in the past in connection with all aspects of crossflow cooling towers, and particularly the fill assemblies thereof. Thus, various varieties of splash-type fills have been proposed, which in general consist of elongated bars of specific configuration for dispersing descending hot water. Another type of fill heretofore in use is composed of a series of thin, opposed sheets formed of synthetic resin materials. Such fills are designed such that the descending water passes along the sheets in a film, and thus such fills have come to be known as "film fills." Generally speaking, film fills are significantly more efficient than splash-type fills, i.e., they give an enhanced cooling effect as compared with splash bar assemblies. However, film fills are much more expensive than splash units, and for this reason have not totally supplanted the latter.
U.S. Pat. No. 3,917,764 describes a combination fill assembly, i.e., one which employs both film fill sections and splash bars. However, the film assembly disclosed in the '764 patent is deemed deficient in a number of important respects. First, the film fill packs employed are oriented in the manner of a counterflow fill. That is to say, the air entrance faces of the film fill packs are coincident with the water exit faces, and correspondingly the air exit faces are coincident with the water entrance faces thereof. This orientation of the film fill packs leads to significant airflow disruptions and a tendency for the air to "short circuit", or travel in a diagonal pattern upwardly through the fill assembly. This in turn significantly reduces cooling efficiency.